[技术]Arizona眼睛模型 [复制链接]

简介 B]tIi^  
ZvcJK4hi  
人眼光学模型可用来设计眼科用设备，光学系统注定了要与人眼一起使用。本文演示了这样一个模型：Arizona眼睛模型，在Jim Schwiegerling教授的书中有详细描述：《Field Guide to Visual and Ophthalmic Optics》。AZ眼睛模型达到了基于平均临床数据所决定的轴上和轴外像差等级。FRED文件包含了此眼睛模型及几个用来分析它的光源，并包括一个基于想要的屈光度来调整模型的内嵌脚本。 ?-1r$31p  
YM5fyv?  
模型 :;t #\%L/  
sXNb}gJ  
模型的定义如表1种所示，由半径、圆锥常数、折射率、阿贝数、到下一面的距离等一系列表面组成。一些参数由屈光度（A）来决定。 mrX^2SR  
MDF%\Sx  
P./VmY'  
在FRED中使用0屈光度来创建的，光瞳加在了透镜的前面。材料是创建一个新的材料并选择类型“Model Material”,输入的参数是nd和vd. J,b&XD@m  
c'*a{CV4P  
光源 WJ*n29^N^h  
6oui]$pH  
多个光源定义来分析该模型的不同特性。图1显示了所以的光源和提示信息告诉您他们可以用来做什么。 EUIIr4]  
V2N_8)s9W  
3"F`ZJ]=  
xLx]_R()  
除了“Letter F”之外的所有光源的光线位置设定在了孔径光阑位置处，并增加了pre-propagation distance= -8。尽管光线在光瞳处创建，规定的传输方向相对于光线位置在pre-propagation distance之后。这意味着光束沿着Z轴在眼睛的前面以平行光入射，而不是在光瞳处入射。 Q X%&~  
*b];|n{  
在往下看是内置的脚本用来修改屈光度，使其为4（250mm），光源“Letter F”在视网膜处生成一个字母为F的图像。绿色的光线聚焦的非常好而红色和蓝色光线有一点的模糊。使用Positions Spot Diagram分析工具来观察最为合适。 m*mm\wN5  
NV#FvM/#"  
hR.@b*q?R  
^B+!N;  
视网膜的散射 %Q!`NCe+[  
Mg^e3D1_  
在散射文件中，有一个名为“Retina surface”的72%的反射型朗伯散射，它为视网膜的散射提供了一个粗略的近似。为了模拟来自视网膜的散射，改变自定义元件“Eye ball” 下的视网膜的表面从“halt all” 到”Allow All”。并使几何中“plane”可追迹。 Un6/e/6,  
5O`dO9g}$  
w |l1'   
ntmyNf
?;  
注意在视网膜的表面有散射重点采样规格定义，在“Scatter”标签的底部可获取该信息。“toward pupil”指定散射光朝向光瞳，半角度10度。 GtwT  
Vx @|O%  
$y b4xU  
/EG~sR
vl}  
脚本 <7Ae-!>x  
v(pmI
b{  
内置脚本使用对话框显示屈光度和光瞳直径的数值设置。使用FRED Basic脚本创建和使用对话框非常容易。图6显示了如何获取用户自定义对话框，如下图所示： b"TjGE  
O iFS}p  
nVJPR  
S/ibb&  
如果“OK”按钮按下，将会核对对话框下面的代码行，如果点击取消则脚本终止。然后输入的参数赋予变量，如果此处是保留为空白，则使用默认值。因此，如果没有值输入并点击“OK”按钮，则脚本是以屈光度为0，光瞳直径为4mm来运行的。 \w'*z&`W9  
余下的脚本计算与屈光度有关的所有参数。 "]\+?  
Zk[&IBE_  
分析 i<(Xr  
N:9>dpP}O  
屈光度为4，光瞳直径为4mm，字母F点在视网膜上所成的像。 #0Tq=:AE>  
/x1MPP>fu
 
]~\sA
  
脚本代码 C{d7J'Avk  
I<A6Z&*un  
Option Explicit     'Remove this to enable non-dimensioned variables to be used. JCW\ *R  
|`jjHuQ;  
Dim entity As T_ENTITY QFIL)'K  
Dim op As T_OPERATION !\g
+8>  
Dim mat As T_MODELMATERIAL rLX4jT^  
Dim A As Double M|] "W  
Dim pupilDiam As Double E#F/88(  
Dim eID As Long @&}q}D  
Dim parID As Long GHmv} Z  
Dim count As Integer K).n.:vYZ  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double ~ Uo)0  
Dim tlens As Double, nlens As Double rSYi<ku  
Dim curv As Double, conic As Double OaL\w D^  
Dim ok As Long \.g\Zib )  
 ;vb8G$  
Sub Main  kQ  
,<2DLp%%D  
    '用户输入对话框 Zo{$  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 ce6__f5?  
        TextBox 220,21,40,21,.TextBox1 'default: 0 CNww`PX,zZ  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 #
A8@CA^d  
        OKButton 40,91,90,21 Uw4>v:  
        CancelButton 190,91,90,21 1 tR_8lC  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 WlYs~(=9  
        TextBox 220,49,40,21,.TextBox2 'default: 4 6b!F1
  
    End Dialog XerbUkZ  
    Dim dlg As UserDialog b<]n%Q'n  
AL5Vu$V~n}  
    ok = Dialog (dlg)  RDtU43  
|A8/FU2{  
    If ok=0 Then    'cancel button was pressed 8 B**8yg.  
        Print "Execution cancelled." Sc7U|s  
        End sFBneBub  
    End If c=AOkX3UD  
1 n%?l[o  
    'Assign accommodation and pupil diameter & use defaults if field left empty wR{'y)$  
    If dlg.TextBox1 = "" Then -)~SM&  
        A = 0           'Default accommodation +S))3 5N[  
    Else >s`J5I!  
        A = CDbl(dlg.TextBox1) i%6;  
    End If "}Me}S<  
"HYQqNj?Z  
    If dlg.TextBox2 = "" Then smm
]6  
        pupilDiam = 4   'Default pupil diameter _f6HAGDN  
    Else Pm$q]A~  
        pupilDiam = CDbl(dlg.TextBox2) G7=pBf  
    End If D/=5tOy  
&gI~LP  
    Print " " V#jWege  
    Print "Accommodation = " & A & " Diopters" ?h!i0Rsm  
    Print "Pupil Diameter = " & pupilDiam & " mm" ?2Kt'1s#  
.6OgO{P:  
    ' Calculate new parameters with accommodation lHZU iB  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness .Q)|vq^  
fBQ?|~:n  
    Rant = 12.0 - 0.4*A                     'Radius of anterior lens S1U@UC  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens iKas/8  
cJgBI(S5  
    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens f7I{WfZ\P  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens W(hM
ft%  
GQ_p-/p R  
    tlens = 3.767 + 0.04*A                  'Lens thickness R1Ye<R!Q  
Z`&4SH=j  
    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction &P,^.'  
=YG _z^'  
    'Adjust parameters to account for accommodation pZyQY+O  
eyp,y2Tz  
    '************************************************************************* ?GTU=gpQ  
    'Aqueous thickness (Position of Lens) qT/Do?Y  
    '************************************************************************* %Qmk2  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) sK=0Np=`  
    GetCustomElement eID, entity _uc\ D R  

<58l;<0  
    parID = FindFullName( "Geometry.Arizona Eye" ) v=95_l  
?6!]Nl1gr  
    ' Delete any shift(s) in z {m`A!qcD|  
    count = 0 $F.kK%-*  
    While GetOperationCount(eID)>count {_U Kttp  
        GetOperation eID, count, op %{;Qls%[t  
        If op.Type="ShiftZ" Then -VZRujl  
            DeleteOperation eID,count `m.eM  
            count=count-1 U4G}DCU  
        End If 3DaQo0N  
        count=count+1 _hG;.=sr  
    Wend iE.-FZc  
na^sBq?\  
    'Set new shift in VYw%01#  
    op.Type = "ShiftZ" {7MjP+\  
    op.val1 = taq *1@:'rJ  
    op.parent = parID umLb+GbI4  
    AddOperation eID, op %c)[ kAU!  
    Print "Set aqueous humor thickness = " & taq-0.55  Yav2q3  
h3gWOU  
    '************************************************************************* vKoP|z=m  
    'Radius and conic constant of anterior lens #'4OYY.  
    '************************************************************************* TEsnNi 1  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) dC}`IR  
    GetConic eID, entity, curv, conic !AJ]j|@VBd  
$OVXk'cc  
    SetConic eID, entity, 1/Rant, CCant UhmTr[&  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant wY"o`oZ  
-=698h*  
    '************************************************************************* bAr` E  
    'Radius and conic constant of posterior lens &6Il(3-^  
    '************************************************************************* ^nVl (^{  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) Y\2|x*KwvF  
    GetConic eID, entity, curv, conic 8[ry|J  
zdSh:  
    SetConic eID, entity, 1/Rpost, CCpost 9SMiJad<  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost hnWo|! ,O$  
0uCT+-  
    '************************************************************************* UK*qKj.)  
    'Lens thickness (Position of posterior lens surface) 9N[EZhW  
    '************************************************************************* x
v7"WFb  
9j*0
D("  
    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) 5jq=_mHt  
f=J<*h  
    ' Delete any z-shift(s) fRTo.u  
    count = 0 #
fhEc;t  
    While GetOperationCount(eID)>count %~*jae!f  
        GetOperation eID, count, op 1px\K8  
        If op.Type="ShiftZ" Then H;WY!X$x  
            DeleteOperation eID,count F=)eLE{W  
            count=count-1 6ri\>QrF  
        End If y|_Eu:  
        count=count+1
*@ED}Mj+  
    Wend 1@XgTL4  
(s
w-~U%  
    'Set new z-shift ;LJ3c7$@lf  
    op.Type = "ShiftZ" Y|0ow_oH  
    op.val1 = tlens *Zd84wRSj  
    op.parent = parID LZ
*R[  
    AddOperation eID, op |Y_ -  
    Print "Set lens thickness = " & tlens jJwkuh8R  
}1+%_|Y-E  
    '************************************************************************* !F!3Q4  
    'Lens index of refraction bdh(WJh%  
    '************************************************************************* >qT'z$  
    eID = FindMaterial( "Lens" ) 4}KU>9YRA  
    GetModelMaterial eID, mat 3]E(mRX  
J7-^F)lu-  
    mat.Nd = nlens Hlj6$%.  
    SetModelMaterial eID, mat :XT?jdg  
    Print "Set lens index of refraction = " & nlens g?qKNY  
EY>8O+  
    '************************************************************************* 9
-jO,l  
    'Pupil diameter e9u@`ZC07  
    '************************************************************************* igDyp0t  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) .6T6 S v  
%6 =\5>  
    'Adjust pupil diameter (trimming volume inner hole) F}ukZ DB  
x
Qt 3[(Z  
    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" &:?e&  
'zgvQMu  
    ' Adjust pupil location to just in front of the lens |Svk^mq  
    parID = FindFullName( "Geometry.Arizona Eye" ) w!q&  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) ]"x\=A  
    count = 0 "2HY5AE  
    While GetOperationCount(eID)>count ?p8k{N(1  
        GetOperation eID, count, op I>w^2(y  
        If op.Type="ShiftZ" Then iH)Nk^  
            DeleteOperation eID,count {^RG% &S  
            count=count-1 )@:l^$x  
        End If $T dC/#7  
        count=count+1 Go+[uY^  
    Wend lQt% Qx  
    op.Type = "ShiftZ" Z^tGu7x  
    op.val1 = taq-0.01 <Dw]yGK@  
    op.parent = parID oP$kRfXS!<  
    AddOperation eID, op (M% ;~y\  
c>Z*/>~  
    Print "Set pupil diameter = " & pupilDiam @oH[SWx  
kN'Thq/ZE  
    'Update AZ Eye subassembly Description z<a2cQ?XQ  
    eID = FindFullName( "Geometry.Arizona Eye" ) #w~0uCzQ@  
    GetEntity eID, entity ;A^K_w'  
    entity.Description = "Accommodation = " & A & "D" :Z2tig nL  
    SetEntity eID, entity >riq9
8Us/  
V;[p438o  
    Update +0#JnqH"  
    Print "DONE!" 8j\d~Lw=  
     ~'BUrX\  
End Sub aV|k}H{wt  
^LO]Z  
如果屈光度是4，光瞳直径是4，则会输出如下数据： +J40wFI:y  
:Ee?K  
Accommodation = 4 Diopters r>3^kL5UI  
Pupil Diameter = 4 mm F_PTMl=Q|J  
Set aqueous humor thickness = 2.81 q,,j',8kq/  
Set anterior lens radius = 10.4 and conic constant = -2.375869 T]2U fi.  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 +sn2Lw!^  
Set lens thickness = 3.927 T7GQ^WnA  
Set lens index of refraction = 1.42672 eti9nPjG  
Set pupil diameter = 4 jyjQzt >\  
DONE! :_c*m@=z(